Process for manufacturing a cast metal heat exchanger housing for a vehicle heater

Abstract

A process for manufacturing a cast metal heat exchanger housing ( 12 ) for a vehicle heater having a pot-shape housing wall ( 14 ) extending in a direction of a housing longitudinal axis (L) and having a plurality of heat transfer ribs ( 22 ) extending on an outer side of the housing wall ( 14 ) in the area of a circumferential wall ( 16 ) and in the area of a bottom wall ( 18 ) of the housing wall ( 14 ) in the direction of the housing longitudinal axis (L). The process includes metal casting wherein a sprue cross-sectional area including at least some of the heat transfer ribs ( 22 ). The cast metal heat exchanger housing has an axial end face formed upon cutting off metallic material that is essentially at right angles to the housing longitudinal axis and extends into an area of at least some of the heat transfer ribs.

What is claimed is: 
     
       1. A process for manufacturing a cast metal heat exchanger housing, the process comprising:
 metal casting the metal heat exchanger housing comprising a vehicle heater pot-shape housing wall elongated in a direction of a housing longitudinal axis and comprising a plurality of heat transfer ribs extending in the direction of the housing longitudinal axis on an outer side of the housing wall in an area of a circumferential wall of the housing wall and in an area of a bottom wall of the housing wall, wherein a sprue cross-sectional area provided in a casting mold, through which molten metallic material is poured during the metal casting, comprises, in a plane that is at right angles to the housing longitudinal axis, a central runner and, starting from the central runner, at least some of the heat transfer ribs; 
 subsequent to the metal casting, cooling of the metallic material; and 
 subsequent to the cooling, cutting off a sprue from the heat exchanger housing at a location corresponding to the plane that is at right angles to the housing longitudinal axis to form an axial end face of the heat exchanger housing, which axial end face corresponds to the sprue cross sectional area provided in the casting mold at the plane that is at right angles to the housing longitudinal axis and is at right angles to the housing longitudinal axis and extends into the area of at least some of the heat transfer ribs. 
 
     
     
       2. The process in accordance with  claim 1 , wherein the sprue cross-sectional area comprises a plurality of diagonal ribs starting from the central runner. 
     
     
       3. The process in accordance with  claim 2 , wherein the plurality of diagonal ribs comprise four diagonal ribs that extend starting from the central runner and wherein:
 two of the diagonal ribs extend diametrically in relation to one another away from the central runner; or 
 diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another; or 
 two of the four diagonal ribs extend diametrically in relation to one another away from the central runner and diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another. 
 
     
     
       4. The process in accordance with  claim 2 , wherein:
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area and at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area. 
 
     
     
       5. The process in accordance with  claim 1 , wherein:
 the heat transfer ribs are arranged in a plurality of groups; and 
 the heat transfer ribs of each group of heat transfer ribs are arranged essentially parallel to one another. 
 
     
     
       6. The process in accordance with  claim 1 , wherein:
 the sprue cross-sectional area comprises a plurality of diagonal ribs starting from the central runner; and 
 upon cutting off of the sprue, the axial end face is formed extending into the diagonal ribs. 
 
     
     
       7. The process in accordance with  claim 6 , wherein:
 upon cutting off of the sprue, the axial end face is formed with an end face area of a central attachment; 
 upon cutting off of the sprue, the axial end face is formed with end face areas of the diagonal ribs; or 
 upon cutting off of the sprue, the axial end face is formed with an end face area of a central attachment and with an end face areas of the diagonal ribs. 
 
     
     
       8. The process in accordance with  claim 1 , wherein:
 the heat transfer ribs are arranged in a plurality of groups; 
 the heat transfer ribs of each group of heat transfer ribs are arranged essentially parallel to one another; and 
 upon cutting off the sprue, the axial end face is formed with end face portions extending into the groups of the heat transfer ribs. 
 
     
     
       9. A cast metal heat exchanger housing for a vehicle heater, the cast metal heat exchanger housing comprising:
 a pot-shape housing wall elongated in a direction of a housing longitudinal axis; and 
 a plurality of heat transfer ribs extending in the direction of the housing longitudinal axis on an outer side of the housing wall in an area of a circumferential wall of the housing wall and in an area of a bottom wall of the housing wall, wherein an axial end face of the heat exchanger housing, which axial end face is formed upon cutting off metallic material and is at right angles to the housing longitudinal and extends into an area of at least some of the heat transfer ribs, wherein the cast metal heat exchanger housing is formed by a process comprising: 
 metal casting the metal heat exchanger housing with a sprue cross-sectional area provided in a casting mold, through which molten metallic material is poured during the metal casting, comprising, in a plane that is at right angles to the housing longitudinal axis, a central runner and, starting from the central runner, at least some of the heat transfer ribs; 
 subsequent to the metal casting, cooling of the metallic material; and 
 subsequent to the cooling, cutting off a sprue from the heat exchanger housing at a location corresponding to the plane that is at right angles to the housing longitudinal axis to form an axial end face of the heat exchanger housing, which axial end face corresponds to the sprue cross sectional area provided in the casting mold at the plane that is at right angles to the housing longitudinal axis and is at right angles to the housing longitudinal axis and extends into the area of at least some of the heat transfer ribs. 
 
     
     
       10. The cast metal heat exchanger housing in accordance with  claim 9 , wherein the plurality of heat transfer ribs comprise diagonal ribs extending radially outwards from a central attachment extending from the bottom wall essentially coaxially in relation to the housing longitudinal axis. 
     
     
       11. The cast metal heat exchanger housing in accordance with  claim 9 , wherein the sprue cross-sectional area comprises a plurality of diagonal ribs starting from the central runner. 
     
     
       12. The cast metal heat exchanger housing in accordance with  claim 11 , wherein the plurality of diagonal ribs comprise four diagonal ribs that extend starting from the central runner and wherein:
 two of the diagonal ribs extend diametrically in relation to one another away from the central runner; or 
 diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another; or 
 two of the four diagonal ribs extend diametrically in relation to one another away from the central runner and diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another. 
 
     
     
       13. The cast metal heat exchanger housing in accordance with  claim 11 , wherein:
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area and at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area. 
 
     
     
       14. The cast metal heat exchanger housing in accordance with  claim 9 , wherein:
 the heat transfer ribs are arranged in a plurality of groups; and 
 the heat transfer ribs of each group of heat transfer ribs are arranged essentially parallel to one another. 
 
     
     
       15. The cast metal heat exchanger housing in accordance with  claim 9 , wherein:
 the sprue cross-sectional area comprises a plurality of diagonal ribs starting from the central runner; 
 upon cutting off of the sprue, the axial end face is formed extending into the diagonal ribs. 
 
     
     
       16. The cast metal heat exchanger housing in accordance with  claim 15 , wherein:
 upon cutting off of the sprue, the axial end face is formed with an end face area of a central attachment; 
 upon cutting off of the sprue, the axial end face is formed with end face areas of the diagonal ribs; or 
 upon cutting off of the sprue, the axial end face is formed with an end face area of a central attachment and with an end face areas of the diagonal ribs. 
 
     
     
       17. A process for manufacturing a cast metal heat exchanger housing, the process comprising:
 metal casting the metal heat exchanger housing comprising a vehicle heater pot-shape housing wall elongated in a direction of a housing longitudinal axis and comprising a plurality of heat transfer ribs extending in the direction of the housing longitudinal axis on an outer side of the housing wall in an area of a circumferential wall of the housing wall and in an area of a bottom wall of the housing wall, wherein a sprue cross-sectional area provided in a casting mold, through which molten metallic material is poured during the metal casting, comprises, in a plane perpendicular to the housing longitudinal axis, a central runner and, starting from the central runner, at least some of the heat transfer ribs; 
 cooling the metallic material after metal casting the metal heat exchanger housing; and 
 cutting off a sprue from the heat exchanger housing at a location corresponding to the plane that is at right angles to the housing longitudinal axis to form an axial end face of the heat exchanger housing after cooling the metallic material, the axial end face being provided in the casting mold at the plane perpendicular to the housing longitudinal axis and the axial end face being perpendicular to the housing longitudinal axis and extending into the area of at least some of the heat transfer ribs, the axial end face having an axial end face shape, the sprue cross sectional area having a sprue cross sectional area shape, wherein the axial end face shape is the same as the sprue cross sectional area shape. 
 
     
     
       18. The process in accordance with  claim 17 , wherein the sprue cross-sectional area comprises a plurality of diagonal ribs starting from the central runner. 
     
     
       19. The process in accordance with  claim 18 , wherein the plurality of diagonal ribs comprise four diagonal ribs that extend starting from the central runner and wherein:
 two of the diagonal ribs extend diametrically in relation to one another away from the central runner; or 
 diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another; or 
 two of the four diagonal ribs extend diametrically in relation to one another away from the central runner and diagonal ribs arranged directly adjacent to one another in a circumferential direction are arranged essentially at right angles to one another. 
 
     
     
       20. The process in accordance with  claim 18 , wherein:
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area; or 
 at least some of the heat transfer ribs extend starting from the central runner in the area of the sprue cross-sectional area and at least some of the heat transfer ribs extend starting from the diagonal ribs in the area of the sprue cross-sectional area.